Method for making phenates



Aug. 29, 1933. J. J. GREBE El AL 1 METHOD FOR MAKING PHENATES Filed June' 29, 1928 E L 4 C J INVENTOR. .707: I fire be arid By affl/a'afflfian Mam/v5 s.

Patented Aug. 29, 1933 t 1 I V i 1,924,31 3

UNITED STATES PATENT. OFFICE- METHOD FOR MAKING PHENATES I John J. Grebe and Willard H. Dow, Midland,

Mich, assignors to The Dow Chemical Company, Midland, Mich., a Corporationof Michigan Application June 29, 1928. Serial No. 289,200

.9 Claims. (01. 260-154) In the processing of liquidmixtures to carry and the following description setting forth in out a chemical reaction taking place under 0011- detail several modes of carrying out the invention, ditions of high temperature and pressure, it has such disclosed modes illustrating, however, ,but been the practice to heat the reacting mixture several of the various ways in which the prin-,

5 Within a suitable container or autoclave by forcciple of the invention may be used. V ing heat from the outside through the walls In said annexed-drawingw thereof, and in large scale working particularly to Fig. 1 shows in diagrammatic form one form .pass a continuous stream of the reaction mixture of apparatus suitable'for carrying out the presthrough a tubular heating and reaction system ent improved process; and Fig. 2 is a portion of 10 in which the mixture is brought up to the desired a Mollier chart of steam showing the availability temperature by forcing the necessary heat of the latter as a component in a reaction acthrough the walls of the tubular container. cording. to such process}, 7

When operating in this manner, whether the Referring more particularly to Fig. 1 of the heat head be high or low, the temperature of the drawing, pump 1 is used to deliver a predeter- 15 source of heat will be higher than the temperamined p tio o a Volatili ab fi C mD t O ture to be attained by the fluid in the system. the reaction mixture, for example water, to a This in itself gives rise to the problem of injury suitable heater, such as coil 2,-installed ina heatto the metallic apparatus, since variations in the ing furnace or chamber 3. Such heated come efficiency of combustion, in the rate of heat losses ponent then passes to a mixer 4, shown as of the 20 and in 'furnace temperature, affect thetemperainjectortype, where it is thoroughly mixed with ture of the metal overa considerable range and the remaining components of the reaction mixtend to subject it to temperatures in excess of ture, these being forwarded by a pump 7 through those at which it can be successfully maintained a preheater coil 6 which may be heated in any owing to weakening of corrosion from without convenient manner. The reaction mixture hav- 5 or within. ing been thoroughly mixed and brought to the We have discovered a method of heating ap-' proper reaction temperaturein mixer 4, then plicable to a reaction mixture which eliminates passes tora suitable reaction chambersuch ascoil. to ajlarge extent the difficulties encountered in 8 inclosed in a chamber 9, which isheat insupast practice. Generally stated, this method conlated, or otherwise arranged and construotedso 30 sists in introducing the reaction materials into that the temperature of the reaction mixture in the pressure system in two or more separate porcoil 8 will not fall materially. The reacted mix-r tions, one suitable portion being heated in any ture then passes out of reactor 8 through pipe suitable manner under pressure to a temperature 10 to suitable receivers and equipment (not above that desired for the reacting mixture and shown) where the reaction products are sepathen being joined to the remaining constituents rated in any satisfactory manner, such as by I of the mixture with which it is mixed. Such re-a distillation.

maining constituents may, if desired, be also pre- Fig. 2 shows a few high pressure lines on a heated to a degree, but the excess heat carried Mollier chart of steam, such lines illustrating in by such first constituent, or portion of the reactgeneral that even though the heat of vaporizaing mixture, when given up to the mixture serves tion vanishes at the critical point, the specific eifectively to heat the entire mixture to the proper heat of-the fluid above the critical pointis high temperature for reaction. Where one ingredient enough to make possible the addition -of consid of the reaction mixture is volatilizable, at least .erably more heat to the fluid where it is availw a portion of such ingredient may be separately able for heating a mixture to the desired re- 1 45 heated and volatilized and also superheated beaction temperature. fore being added to the balance of the reaction When working with mixtures of alkaline solumixture, or a component of the reaction mixture tions and chlorinated hydrocarbons at high pre'scontaining such ingredient may be heated and sures and temperatures, as for thepioduction the volatilizable ingredient vaporized, such treatof phenates, excessive temperatures to which the ment to' precede mixing of the reaction commetallic apparatus is subjected result in' local 5 ponents. corrosion and solution of the metal and deposit To the accomplishment of the foregoing and of same as an oxide in the cooler part of the .related ends, the invention, then, consists of the system, with the result that thevessel or tubing steps hereinafter fully described and particularly may soon be perforated in the hot portion or 5 pointedoutin,theclaims, the annexed drawing stopped up in the cooler portion of the system.

pressures are reached that involve conditions of metal attack.

Accordingly, when it is desired, for example, to react a fluid mixture containing water at aternperature corresponding to a reaction pressure of 1600 lbs. absolute, a marked advantage is obtained by separately heating and vaporizing enough of the water at a pressure in excess of 1600 lbs. absolute, for instance, 1700 lbs. absolute, so that when it is supplied to the remaining constituents of the reaction mixture which have been preheated to a lower temperature than that'of reaction, it will bring the mixture, 1. e., condensed. vapor and preheated liquor, to the desired re action temperature. By superheating the Vapor so used before introduction into the system, the heating efiect per unit weight thereof is raised and less of it is therefore required for producing a given temperature rise, considering the same preheat temperature as before. lower preheat temperature is desired, it Will only be necessary to furnish the additional heat by means of the superheated vapor.

'If the above process is carried out in a continuous system, such as illustrated in Fig. 1, a controlled portion of the total water will be fed in regulated amount through coil 2 operated as a vaporizer to produce therein Water vapor at the excess pressure, say 1700 lbs. absolute. The balance of the reaction mixture is then forced into the system' through 'preheater 6 wherein it is heated to a temperature short of the final temthe temperature to be attained. The vapor and balance of the reaction mixture thereupon come together and mingle in the reactor 8 Where the heat of vaporization and superheat of the Water, and its sensible heat above the reaction temperature, are absorbed by the mixture, whereby the temperature is raised to the desired'degree. In

this manner it becomes unnecessary to drive heat into the reacting mixture through the metal Wall of the reactor, or other part of the apparatus employed, and overheating of such metal is thereby avoided, together with the harmful consequences due to such overheating.

' The foregoing procedure is particularly applicable to processes that have to be carried out at temperatures whichare above the'temperature corresponding to the critical pressure of the volatilizable components of the reaction mixture. For example, in the manufacture of sodium phenate from'a mixture of chlorobenzene, caustic soda and Water, to which reference has been already made, it is'necessary to bring the temperature of themixture under suitable pressure up to a satisfactory reaction point, for instance 320 C. at a pressure of 250 atmospheres. Steam at 400 C. under this pressure will contain approximately 264 kilogram calories more heat per kilogram than water at 320 C. and the same pressure- This heat is therefore available to raise the temperature of the reactin ingredients from their initial temperature to 320 C. Accordingly the percent by wei ht of the total mixture which must be added to the mixture in the form of steam at 400 C. is by proportion approximately 52 percent, when the initial temperature at which the reacting components are utilized is approximately room temperature. Similarly, it is seen If, however, a'

by proportion that if the reaction mixture is preheated to 200 C., it will only be necessary to heat approximately 32 percent of the water to steam at 400 C. in order to bring the mixture to the desired reaction temperature.

In some cases the reaction mixture may be sufficiently mixed in mixing device. 4, where it is brought into reactive relation at the proper temperature so that the reaction may pass immediately to substantial completion allowing the products of. the reaction to be vented at once as at controlled outlet 15. If a longer time is required for the reaction'to proceed, the mixture is then passed to a suitable reaction chamber, such I as coil 3 or its equivalent, from whence it can be vented through controlled outlet 10 to a suitable receiver as previously disclosed.

It will be understood that the temperature to which the component heated in coil 2, or equivalent chamber is raised, is a higher temperature than that required for the reaction mixture. It will further be seen that this method of heating the reacting mixture in divided stream permits bringin the ingredients up to reacting temperature suddenly upon mixing and avoids bringing them together at lower temperatures, which in some cases has a disadvantageous effect upon the reaction, or the efficiency thereof. missible in certain cases to heat one of the ingredients of a reacting mixture-to a temperature It is peri but is is not permissible to heat other ingredients to a high temperature or to even the reaction temperature gradually. The present improved method there; re enables the absorption of the heat for the reaction temperature in that portion of the mixture which may be permissibly heated to a higher temperature than that to which it would be permissible or advantageous to heat the entire mixture, or other portions thereof, previous to reactive contact of the ingredients. The advantage of separate heating is also realized in avoiding attack of metallic apparatus which occurs at high temperatures due. to the corrosive action of certain of the ingredients ofreacting mixtures. Such ingredients in the herein disclosed method need be preheated to av moderate temperature only, thereby avoiding in part or altogether attack on metal surfaces of the apparatus consequent upon prolonged contact thereof with such corrosive ingredients at the higher temperature required for the chemical reaction.

Other modes of applying the principle of our invention may be employed insteadofthose ex.- plained, change being made as regards the methods herein disclosed, provided the step or steps stated by any of the following claims or the equivalent of such stated step or steps be em.- ployed.

We therefore particularly point out and. distinctly claim as our invention:

1. In a method for making. a phenate, the steps which consist in preparing a mixture of. a mono haiogenated benzene and a water solution of a caustic alkali under pressure in excess of the Va por pressure to be later developed, but at .a temperature below the temperature of reaction and then heating said mixture to the reaction temperature by injecting thereinto steam of a high- .er pressure superheated to a temperature in exdroxide under pressure in excess of the vapor pressure to be later developed, but at a temperature belowthe temperature of reaction and then heating said mixture to the reaction temperature by injecting thereinto steam of a higher pressure superheated to a temperature in excess of the reaction temperature desired. 7

3. In a method for making a phenate, the steps which consist in preparing a mixture of a halogenated benzene and a water solution of a caus tic alkali under pressure in excess of the vapor pressure to be later developed, but at a temperature below the temperature of reaction and then heating said mixtureto the reaction tempera ture by injecting thereinto steam of a higher pressure superheated to a temperature in excess of the reaction temperature desired.

4. In a method of making a hydroxy aromatic hydrocarbon, the steps which consist in heating under pressure a mixture of a halogenated aromatic hydrocarbon and an aqueous solutionof a basic hydrolytic agent, and intermixing therewith while still under pressure, an additional aqueous component which has been superheated sufficiently to raise the mixture to the reaction temperature.

5. In a method of making sodium phenate, the steps which consist in preparing a mixture of monochlorobenzene and aqueous sodiumhydroxide under pressure but at a temperature below 320 C., and then heating said mixture to substantially 320 C. by injecting thereinto steam of a higher pressure superheated above 320 C.

6. In a method of effecting a chemical reaction between an aqueous alkaline component and an aromatic compound capable of being hydrolyzed therewith to form a phenate by heating the same together under pressure, the steps which consist in mixing such alkali and aromatic compound, preheating the same to a temperature below the reaction temperature and injecting thereinto steam at a temperature and pressure suflicient to raise the resultant mixture to the reaction temperature. i I

7. In a method of effecting a chemical reaction between an aqueous alkaline component and an aromatic compound capable of being hydrolyzed therewith to form a phenate by heating the same together under pressure, the steps which consist in mixing such alkali and aromatic com: pound, preheating the same to a temperature below the reaction temperature and injecting thereinto steam superheated to a temperature above the desired reaction temperature in amount suificient to raise the preheated mixture to the reaction temperature.

.8. In a method of making a phenate, the steps; which consist in preparing a mixture of a halogenated aromatic hydrocarbon and an aqeuous caustic alkali, preheating the same toza temperature'below the reaction temperature and injecting thereinto steam at a temperature and pressure sufiicient to raise the preheated mixture to the reaction temperature. 7

9. In a method of making sodium phenate, the steps which consist in preparing a mixture 01' monochlorobenzene and an aqueous sodium-hy- 'droxide solution, preheating the same to a temperature below the reaction temperature and injecting thereinto, steam at a temperature and pressure sufilcient to raise the preheated mixture to the reaction temperature.

" JOHN, J. GREBE. I

WILLARD H. DOW. 

